SAN FRANCISCO — US software giant Microsoft beat the expectations of Wall Street analysts on Thursday despite the weak market for personal computers.

The Redmond, Washington-based Microsoft said net profit rose 31 percent to $5.23 billion in the third quarter of its fiscal year while revenue increased 13 percent to $16.43 billion.

Earnings per share of 61 cents were better than the 56 cents forecast by analysts.

"We delivered strong financial results despite a mixed PC environment, which demonstrates the strength and breadth of our businesses," Peter Klein, Microsoft's chief financial officer, said in a statement.

"Consumers are purchasing Office 2010, Xbox and Kinect at tremendous rates, and businesses of all sizes are purchasing Microsoft platforms and applications," Klein said.

Microsoft said Windows 7 was the fastest selling computer operating system in history with 350 million licenses sold although revenue for the segment was down four percent in the quarter to $4.4 billion, in line with PC trends.

Microsoft said revenue at its business division grew 21 percent and Office 2010 has become the fastest selling version of the productivity suite ever.

Microsoft said computer server and tools revenue was up 11 percent while the online services division saw revenue grow 14 percent, mainly through increases in revenue from search engine Bing.

Revenue grew 60 percent in the entertainment and devices division, primarily from the Kinect motion-controller for the popular Xbox 360 game console.

Microsoft shares were down 1.98 percent at $26.18 in after-hours trading.